Background. Inadequate combination of prescription drugs with nutrients or plants can generate adverse effects or unexpected therapeutic results. The systematic review on this subject will favor the access to compiled information, of a scientific nature, on the possible interactions derived from the joint administration of drugs with nutrients or plants.
Aim. Synthesize the scientific evidence on the clinically relevant aspects of drugnutrient and drug-plant interactions in the pharmacological treatment of epilepsy.
Methodology. A qualitative systematic review of articles of primary origin on the interaction between phenytoin and nutrients or plants.
Results. 816 articles were obtained by applying search equations for this study and 14 of them were selected according to the established criteria. In five of them, the absence of interactions were reported; in three, improvement in drug absorption; in one, increased toxicity; in three, synergism interactions were identified and, in two, inhibition of the anticonvulsant effect.
Conclusions. The joint administration of macronutrients with phenytoin does not generate pharmacological interactions in some cases, although there are exceptions in which synergism, inhibition of pharmacological effect or improved absorption occurs. With reference to micronutrients, pyridoxine and folic acid produce synergism. In addition, supplemented folic acid and piperine, a constituent of black pepper, improve the anticonvulsant absorption while the joint administration of phenytoin with the commercial product "Noni Juice" (Morinda citrifolia L.), generates inhibition of the anticonvulsant effect. On the other hand, Rhodiola rosea produces increased toxicity of phenytoin.